A database generally includes a collection of information or data organized in a way that computer programs can quickly access or select desired portions of the collection. A common type of database is the relational database, which stores data in logical structures called tables. Databases, including relational databases, can be accessed and modified using a database management system (DBMS). Several relational DBMS products are available from companies such as Oracle Corporation®, IBM®, and Microsoft® as well as from various open-source vendors.
Users can access relational databases using database statements such as Structured Query Language (SQL) statements. Because some SQL statements take longer to process than others, database administrators (DBA) often tune these statements to adjust their performance. In the average DBMS, there may be hundreds or thousands of SQL statements that a DBA reviews and evaluates to determine what to tune.